We start this issue with a look at the most ubiquitous species on the planet* – Prochlorococcus; a bluegreen algae (or photosynthesising bacterium if you want to be rude) that has adapted to life in the open ocean, but relies on other friendly bugs to do it. We also see the sequencing of the first crustacean genome; the child microscopist’s friend – the water flea!

In the conservation section we have news of more reports in the Census of Marine Life (CoML) series, covering South America, the Indian Ocean and the Gulf of Maine. While the Indian Ocean study suffers from a lack of core data, the US study provides a wealth of information, and a valuable insight into temperate marine ecosystems. We also have a nice paper looking at how penguins have fared since the 1970’s, when water temperatures changed in the southern Indian Ocean (but no formal climate change section this time).

Marine science

Friends in high places: The mid oceans are very nutrient poor, and have been colonised by the specialist cyanobacterium Prochlorococcus. It has a number of adaptations to this environment including small size, small genome, use of sulfo-lipids as replacements for phospholipids. It is very successful, living in high densities, and may be responsible for 50% of all photosynthesis in the oceans! There are a number of types of Prochlorococcus adapted to life at different depths. This paper looks at its dependence on friendly heterotrophic bacteria that catalyse the breakdown of peroxide, which is present at highest concentration in surface waters. In thier absence Prochlorococcus might be confined to deeper waters. It is not clear what the helper heterotrophic bacteria get out of the deal.
Morris JJ, Johnson ZI, Szul MJ, Keller M, Zinser ER (2011) Dependence of the Cyanobacterium Prochlorococcus on Hydrogen Peroxide Scavenging Microbes for Growth at the Ocean’s Surface. PLoS ONE 6(2): e16805. doi:10.1371/journal.pone.0016805

Species on the mount: An ROV has been used to carry out a survey of life on the Vercelli Seamount in the North Tyrrhenian Sea. The survey was conducted at depths between 100 and 60m, and showed dense kelp forests at the top of the site, with communities of filter feeders living down the sides.
Bo M, Bertolino M, Borghini M, Castellano M, Covazzi Harriague A, et al. (2011) Characteristics of the Mesophotic Megabenthic Assemblages of the Vercelli Seamount (North Tyrrhenian Sea). PLoS ONE 6(2): e16357. doi:10.1371/journal.pone.0016357

Daphnia a first: Daphnia pulex, the water flea, has become the first crustacean to have its genome fully sequenced. ScienceDaily (Feb. 3, 2011) It is reported to have more genes than any other animal sequenced to date. ScienceDaily (Feb. 3, 2011). More information about the Daphnia sequence is provided by Dr Bik at Deep Sea News (February 4th, 2011).

Seven cryptic blennies: DNA analysis has been used to show that three species in the genus Starksia are actually seven species. ScienceDaily (Feb. 5, 2011) [A quick review of Catalogue of Life and FishBase indicate that no species of Starksia are native to the Eastern Atlantic, though we have plenty of other blennies…]

Boy or girl? Sex changes in wrasse is a subject that is brought up pretty much every time we (Lancashire MCS) do a lecture on fish. To cut a long story short, fish are not as fixed in their choices as mammals! This paper looks at how sex is determined at a molecular level in a sea bream (Sparus aurata L.). Most sea bream start their life as males – in this study, at two years of age, only 3% of the population was found to be female! As the population ages, more males switch sex, and females eventually dominate older generations. No sex chromosomes have been detected in sea bream, and social and environmental factors are thought to trigger sex reversal. In this paper the authors believe that they have identified the region of the genome that responds to these environmental factors, and trigger the change in sex. [I was uncertain reading the paper whether or not the authors impute that fish weight is an important trigger for sex reversal].
Loukovitis D, Sarropoulou E, Tsigenopoulos CS, Batargias C, Magoulas A, et al. (2011) Quantitative Trait Loci Involved in Sex Determination and Body Growth in the Gilthead Sea Bream (Sparus aurata L.) through Targeted Genome Scan. PLoS ONE 6(1): e16599. doi:10.1371/journal.pone.0016599

Fighting parasites: Animals detect infection with immune receptors – complex proteins found in the cell’s membranes. Each group of animals (reptiles, fish, mammals, amphibians) has different types of receptor. In this paper a new receptor found in fish (carp) is described. This responds to infection of the fish by protozoan parasites.
Ribeiro CMS, Bird S, Raes G, Ghassabeh GH, Schijns VEJC, et al. (2011) A Novel Soluble Immune-Type Receptor (SITR) in Teleost Fish: Carp SITR Is Involved in the Nitric Oxide-Mediated Response to a Protozoan Parasite. PLoS ONE 6(1): e15986. doi:10.1371/journal.pone.0015986

Thymus they are a’changin’: Lampreys have a version of the thymus located within their gills. The thymus is located between the lungs in humans, and produces T lymphocytes, white blood cells that are key for managing the immune system. ScienceDaily (Feb. 2, 2011)

Shell midden: Here’s a fun collection of archaeo- and paleo- marine life. Kevin Zelnio in Deep Sea News, on February 2nd, 2011. [Shell middens are really common archaeological features, though often over-looked as ‘sand dunes’. There are some excellent ones on the Western Isles reaching heights of several metres. These had been refuse dumps for millenia, picking up a fascinating record of how the locals were using the marine resource].

Conservation

Protected area management in the high seas: How and why do you manage an area of open sea, with continually changing conditions, and populations? This paper focusses on the southern Benguela and Agulhas Bank ecosystems, renowned for their high productivity, off the coast of South Africa. It looks at water movements and primary production, and how these translate up the food chain. It plots species richness and bycatch, and compares models in which protected areas are moved around within the region to maximise pelagic and benthic species diversity, and improve fisheries sustainability.
Grantham HS, Game ET, Lombard AT, Hobday AJ, Richardson AJ, et al. (2011) Accommodating Dynamic Oceanographic Processes and Pelagic Biodiversity in Marine Conservation Planning. PLoS ONE 6(2): e16552. doi:10.1371/journal.pone.0016552

δ¹³C Penguins: Variation in carbon-13 isotope ratios in penguin feathers have been used to follow changes in carrying capacity of the southern Indian Ocean. The work shows that there was a decline in food resources following a temperature change in the 1970’s, but that this was not uniform over the entirety of the region. The change in carrying capacity may in part be causing the decline in numbers of subtropical and subantarctic species of penguin that has occurred since this date.
Jaeger A, Cherel Y (2011) Isotopic Investigation of Contemporary and Historic Changes in Penguin Trophic Niches and Carrying Capacity of the Southern Indian Ocean. PLoS ONE 6(2): e16484. doi:10.1371/journal.pone.0016484

2011, year of the turtle: Half of all species of turtles are threatened, and are likely to experience further threats in coming decades from habitat loss and exploitation. The authors suggest protecting rare species and managing common ones to prevent future problems. ScienceDaily (Feb. 2, 2011)

Eel be all right? Attempts are being made to understand the life history of the Eel (Anguilla anguilla), which is suffering a steep decline in numbers in Europe. This study indicates that there is very high mortality (60%) as the eels leave their rivers, right at the start of their long migration to the Sargasso Sea to breed. Much of the mortallity seems to be being caused by anglers and commercial fishermen. ScienceDaily (Feb. 1, 2011)

CoML series reports

Marine biodiversity in South America: This review is part of the CoML series, and looks at the marine life discovered in the geographical subregions around the sub-continent. It also looks at threats to biodiversity, and reviews conservation strategies for each sub-region. Fisheries are the greatest threat to vertebrates in all areas, with many areas being over-exploited. Habitat degredation, due to coastal development and discharge of pollutants, and the introduction of exotic species are noted as threats to all plant and animal groups in many sub-regions. Oil exploitation is noted as a threat in the Tropical West Atlantic region. Conservation efforts are generally in early stages, with some protected areas being planned or recently introduced.
Miloslavich P, Klein E, Díaz JM, Hernández CE, Bigatti G, et al. (2011) Marine Biodiversity in the Atlantic and Pacific Coasts of South America: Knowledge and Gaps. PLoS ONE 6(1): e14631. doi:10.1371/journal.pone.0014631

Marine biodiversity in the Indian Ocean: The Indian Ocean covers 30% of the world’s oceans by area, but background data is missing over most of this region, and where it does exist, it is usually restricted to corals, fish and molluscs. Major threats are the loss of mangroves, commonly for shrimp farms, plus eutrophication due to domestic and agricultural run-off. Over-exploitation of fish stocks is reported in many areas, though the authors know of no extinctions caused by this as yet. There are problems with enforcement of basic fisheries protection measures.
Wafar M, Venkataraman K, Ingole B, Ajmal Khan S, LokaBharathi P (2011) State of Knowledge of Coastal and Marine Biodiversity of Indian Ocean Countries. PLoS ONE 6(1): e14613. doi:10.1371/journal.pone.0014613

Gulf of Maine ecosystem: How the diversity of zooplankton and nekton change with time, distance from shore and depth. Copepods show considerable variation in species richness across different years, with good years having twice the diversity of poor years. Total biomass is seen to change with both fisheries pressure and changes in environmental factors, but while some species are depleted (e.g. herring due to commercial pressure) other small species tend to take over. Total biomass shows an underlying increasing trend between 1965 and 2010. There is discussion of possible changes to the ecosystem in the light of climate change is made, as one of the important copepod polulations (Calanus finmarchicus), is close to its distribution limit.
Johnson CL, Runge JA, Curtis KA, Durbin EG, Hare JA, et al. (2011) Biodiversity and Ecosystem Function in the Gulf of Maine: Pattern and Role of Zooplankton and Pelagic Nekton. PLoS ONE 6(1): e16491. doi:10.1371/journal.pone.0016491

Fisheries and exploitation

Insights into IPNV: Infectious pancreatic necrosis virus causes contagious diseases in freshwater and marine fish, and can cause considerable loss of aquaculture stocks. The gene expression changes caused by the virus is investigated in this paper.
Wang W-L, Hong J-R, Lin G-H, Liu W, Gong H-Y, et al. (2011) Stage-Specific Expression of TNFα Regulates Bad/Bid-Mediated Apoptosis and RIP1/ROS-Mediated Secondary Necrosis in Birnavirus-Infected Fish Cells. PLoS ONE 6(2): e16740. doi:10.1371/journal.pone.0016740

Oysters to go: Wild stocks of oysters have been over-harvested, resulting in a population collapse in many areas, with 85% of oyster reefs world-wide being lost. ScienceDaily (Feb. 4, 2011)

Fish trawled out of the freezer: The catch of fish from arctic waters might be 75 times greater than is being reported to the UN Food and Agriculture Organisation. It seems that most governments simply don’t bother recording or reporting fisheries activity in this region. So much for the un-spoilt wilderness… ScienceDaily (Feb. 4, 2011)

Pollution

Calls for critical environmental data to be gathered to permit human impact to be evaluated in the marine ecosystem. ScienceDaily (Feb. 3, 2011)

P and N map: The use of excessive amounts of phosphorus and nitrogen in fertilizers is a cause of considerable damage to both fresh- and salt-water habitats. This research indicates areas of both over- and under-use of these fertilizers around the globe. ScienceDaily (Feb. 3, 2011)

Would you live here? Estuaries are difficult areas to test for pollutants, with many sediment banks and complex water flow. One way may be to grow sea urchins (Paracentrotus lividus), as the number of growth anomalies appearing during their development appears to reflect toxicity problems. ScienceDaily (Feb. 2, 2011)

Where the oil goes… Modelling how oil and dispersants will interact with the environment following a deep-water blow-out. ScienceDaily (Feb. 1, 2011)

Grant

Mia J. Tegner Memorial Research Grant in Marine Environmental History and Historical Marine Ecology (Deadline 1st April 2011)

* This is my guestimate or factoid for the week, it mightbe true, though I have no evidence to support my assertion… [back]